If two individuals are wearing the same kind of pants prior to having sexual intercourse, then during intercourse, the pants engage in Pants Incest.

When a sister and a brother fuck the same person

That tori is having sexual intercourse with her cousin Jeremiah Beasley

The immortal insult, it is like ur family tree lgbt squared, all other insults are disregarded and sent to the shadow realm.

The only comeback more powerful than ur dad lesbian. Only the most cringe people can use it and usually die from the dog they insulted.

The act of having pure, heterosexual, vanilla sex with a partner that is not related to you in any way. No pissing, shitting, violence, or whatever other unspeakable ask that could be thought of.